scholarly journals Pulsar Magnetospheres: Classical, Quasi-Classical and Quantum Descriptions

2000 ◽  
Vol 177 ◽  
pp. 457-460
Author(s):  
A. A. da Costa
Keyword(s):  
Kinetic Theory ◽  
Quantum Electrodynamics ◽  
Gamma Ray ◽  
Radiation Mechanisms ◽  
Radiative Processes ◽  
High Energies ◽  
Curvature Radiation ◽  
Pulsar Radiation ◽  
Relativistic Kinetic Theory ◽  
Random Curvature

AbstractThe plasma motion in pulsar magnetospheres is no longer classical, but quasi-classical, following stochastic trajectories, when random curvature radiation of high energetic gamma-ray photons takes place. This implies an extension to the relativistic kinetic theory of plasmas. But with high energies involved other quantum radiative processes become important, in the context of vacuum (quantum) electrodynamics. The consequences for pulsar radiation mechanisms will be outlined.

scholarly journals Pulsar Geometrodynamics: Relativistic Radiative Plasma Theory and its Associated Quantum Phenomena

2000 ◽  
Vol 195 ◽  
pp. 385-386
Author(s):  
A. A. da Costa
Keyword(s):  
Kinetic Theory ◽  
Quantum Electrodynamics ◽  
Gamma Ray ◽  
Radiative Processes ◽  
High Energies ◽  
Plasma Motion ◽  
Curvature Radiation ◽  
Plasma Theory ◽  
Quantum Phenomena

Plasma motion in pulsar magnetospheres is quasi-classical due to curvature radiation of highly energetic gamma-ray photons, implying an extension to the kinetic theory of plasmas. But with high energies involved, other quantum radiative processes become important in the context of vacuum (quantum) electrodynamics.

Relativistic Kinetic Theory

2017 ◽  
Author(s):  
Gregory V. Vereshchagin ◽  
Alexey G. Aksenov
Keyword(s):  
Kinetic Theory ◽  
Relativistic Kinetic Theory

scholarly journals The response of an autonomous underwater telescope to high energy neutrinos for the observation of Gamma-ray bursts (GRBs)

2019 ◽  
Vol 22 ◽  
pp. 88
Author(s):  
K. Balasi ◽  
C. Markou ◽  
K. Tzamarioudaki ◽  
P. Rapidis ◽  
E. Drakopoulou ◽  
...  
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Gamma Ray Bursts ◽  
Simulation Program ◽  
Neutrino Detector ◽  
High Energies ◽  
Analytical Studies ◽  
High Energy Neutrinos ◽  
Detector Simulation ◽  
Fast Detector

The response of an underwater neutrino detector is discussed for investigating its performance to the detection of muons and high energy neutrinos. The afformentioned telescope consists of an autonomous battery operated detector string to a central 4-floor tower. In this aim, we utilised a fast detector simulation program, SIRENE, to simulate the hits from Cherenkov photons at ultra high energies (as high as 1020 eV). In order to optimize the detector, analytical studies for different configurations and characteristics of the photo-multiplier tubes inside the optical modules of the telescope was also examined.

scholarly journals Detection of the Geminga pulsar with MAGIC hints at a power-law tail emission beyond 15 GeV

2020 ◽  
Vol 643 ◽  
pp. L14
Author(s):  
◽  
V. A. Acciari ◽  
S. Ansoldi ◽  
L. A. Antonelli ◽  
A. Arbet Engels ◽  
...  
Keyword(s):  
Energy Range ◽  
Power Law ◽  
Gamma Ray ◽  
Low Energy ◽  
Significance Level ◽  
Inverse Compton Scattering ◽  
Curvature Radiation ◽  
Sensitivity Range ◽  
Inverse Compton ◽  
First Time

We report the detection of pulsed gamma-ray emission from the Geminga pulsar (PSR J0633+1746) between 15 GeV and 75 GeV. This is the first time a middle-aged pulsar has been detected up to these energies. Observations were carried out with the MAGIC telescopes between 2017 and 2019 using the low-energy threshold Sum-Trigger-II system. After quality selection cuts, ∼80 h of observational data were used for this analysis. To compare with the emission at lower energies below the sensitivity range of MAGIC, 11 years of Fermi-LAT data above 100 MeV were also analysed. From the two pulses per rotation seen by Fermi-LAT, only the second one, P2, is detected in the MAGIC energy range, with a significance of 6.3σ. The spectrum measured by MAGIC is well-represented by a simple power law of spectral index Γ = 5.62 ± 0.54, which smoothly extends the Fermi-LAT spectrum. A joint fit to MAGIC and Fermi-LAT data rules out the existence of a sub-exponential cut-off in the combined energy range at the 3.6σ significance level. The power-law tail emission detected by MAGIC is interpreted as the transition from curvature radiation to Inverse Compton Scattering of particles accelerated in the northern outer gap.

scholarly journals High-energy emission from gamma-ray bursts

2018 ◽  
Vol 27 (13) ◽  
pp. 1842003 ◽  
Author(s):  
Lara Nava
Keyword(s):  
Gamma Ray ◽  
Theoretical Models ◽  
High Energy ◽  
Gamma Ray Bursts ◽  
Quality Of Data ◽  
Large Area ◽  
High Energies ◽  
Energy Emission ◽  
High Energy Emission ◽  
Very High

The number of gamma-ray bursts (GRBs) detected at high energies ([Formula: see text][Formula: see text]GeV) has seen a rapid increase over the last decade, thanks to observations from the Fermi-Large Area Telescope. The improved statistics and quality of data resulted in a better characterization of the high-energy emission properties and in stronger constraints on theoretical models. In spite of the many achievements and progresses, several observational properties still represent a challenge for theoretical models, revealing how our understanding is far from being complete. This paper reviews the main spectral and temporal properties of [Formula: see text][Formula: see text]GeV emission from GRBs and summarizes the most promising theoretical models proposed to interpret the observations. Since a boost for the understanding of GeV radiation might come from observations at even higher energies, the present status and future prospects for observations at very-high energies (above [Formula: see text][Formula: see text]100[Formula: see text]GeV) are also discussed. The improved sensitivity of upcoming facilities, coupled to theoretical predictions, supports the concrete possibility for future ground GRB detections in the high/very-high energy domain.

scholarly journals Future Facilities for Gamma-Ray Pulsar Studies

2004 ◽  
Vol 218 ◽  
pp. 399-406
Author(s):  
D. J. Thompson
Keyword(s):  
Particle Acceleration ◽  
Neutron Stars ◽  
Gamma Ray ◽  
Large Area ◽  
Space Telescope ◽  
High Energies ◽  
Interaction Processes ◽  
Very High ◽  
Insight Into

Pulsars seen at gamma-ray energies offer insight into particle acceleration to very high energies, along with information about the geometry and interaction processes in the magnetospheres of these rotating neutron stars. During the next decade, a number of new gamma-ray facilities will become available for pulsar studies. This brief review describes the motivation for gamma-ray pulsar studies, the opportunities for such studies, and some specific discussion of the capabilities of the Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) for pulsar measurements.

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